Ribbed strapping

ABSTRACT

Plastic strapping generally rectangular in section of the type used to tie bundles of electrical conductors as in my patented strapping apparatus, U.S. Pat. No. 3,633,633 granted Jan. 11, 1972, is extruded with a plurality of parallel, pointed longitudinal ribs, short in height, which prevent the tape from slipping during reverse feed by the gun.

United States Patent 191 Countryman RIBBED STRAPPING [75] Inventor:Albert J. Countryman, Utica, NY.

[73] Assignee: Ty-Lok Assembly Systems, Inc.,

Utica, NY.

[22] Filed: Sept. 29, 1972 [21] Appl. No.2 293,736

[52] 0.8. CI .L 24/16 PB [51] Int. Cl 365d 63/00 [58] Field of Search140/932; 24/16 PB,

24/30.5 P, 17 AP, 305 R [56] References Cited UNITED STATES PATENTS3,014,506 12/1961 Crimmins et a1. 140/932 Dec. 11, 1973 3,022,557 2/1962Logan 24/17 AP 3,141,221 7/1964 Faulls 24/30.5 R 3,371,390 3/1968Sieglitz i 24/16 PB UX 3,633,633 l/l972 Countryman 140/932 PrimaryExaminer-D0nald A. Griffin Attorney-Richard C. Sughrue et a1.

3 Claims, 3 Drawing Figures 1 RIBBED STRAPPING,

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to improvements in the construction of plastic strapping ofindeterminate length of the type used to tie electrical conductors inbundles.

2. Prior Art Plastic strapping is in common usage to tie bundles ofelectrical conductors. There are generally two different types of suchstrapping. First there are the individual straps with molded heads whichrequire special molds, are wasteful of strapping material, and arecommonly applied by hand. Then there is the indeterminate or indefinitelengthnylon strapping having plain flat surfaces as used with strappingguns and locking devices and as disclosed by my prior US. Pat No.3,633,633granted Jan. 1 l, 1972. This strapping is provided. in rollsand is used asfrequired by the semiautomatic gun.

Problems have arisen in the use of such plain flat sur- One surface .ofthe strapping, the bottom surface 14 as shown and as used in thepatented gun, hasthree identical parallel longitudinal ribs 16. Theseribs are spaced about one-fourth, one-half and three-fourths thedistance across the width W of the strapping face as shown. The heightof each rib Hr is about one-fifth to one-sixth the thickness T so theribs do not interfere with the function of the apparatus. Theconfiguration of each rib is also identical, it includes a pointed tip18 between two inclined sides at an included angle of about 60.

In a typical configuration, the tape or strapping is about 0.086 inchwide W, 0.026 to 0.029 inch thick T, the corners are rounded ona 0.008radius, the ribs are I 0.005 inch high HR, thecenter rib is centeredwith reface strapping, namely slipping in the reverse feed of thestrapping by the gun to tighten or cinch the strap around the bundle ofconductors when the lead end of strapping is held in the locking device.Side slipping of the strapping once it is wrapped around the conductorsis also'a problem, but a lesser one than that of reverse feed slipping.

SUMMARY OFTI- IE INVENTION Thisinvention resides in providinglongitudinal ribs of a desired size and shape on one surface of thestrapping to solve the above mentioned problems-Specifically, aplurality of parallel spaced apart ribs are provided. The ribs arespaced apart across the width of the bottom surface of the tape; theyare of a height small in relation to the thickness of the tape; and theyhave. a sharp point.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevation of the tapeof this invention. FIG. 2 is an end elevation of such'tape. FIG. 3 is abottom plan view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Plastic strapping 10 isformed of DYMETROL virgin nylon, a product of E. I. duPont de NemoursCo. of Wilmington, Del. by extrusion of indeterminate lengths, e. g., inrolls to be used as required. The strapping has a tensile strength ofabout 30,000 psi. The strapping has rounded edges or corners l2 and isapproximately three times as wide W as it is thick T. Such strappingwould be used, in combination with locking devices to tie bundles ofelectrical conductors as disclosed in my prior US. Pat. 3,633,633granted Jan. 11,

gard to the width W and the outer ribs are spaced about 0.02 inch fromthe edges.

Such tape markedly improves the functional performance of the tie andthe gun by the ribs operated upon by the reverse feed mechanism of thegun to provide a uniform tension in the tape during the reverse feedmode. Without the ribs the tape drive would slip on the slippery finishor surface of the tape and it was not'always possible to apply theuniform tension or back feed needed to properly cinch the tape aroundthe bundle or conductors. Moreover, when properly tight ened, the taperibs will dig into theconductor insulation to prevent the tie fromslipping in a direction along the axis of they conductors bound.

I claim: g

1. Plastic strapping for passing around electrical conductors and thelike and tying such conductors in a bundle using a separate lockingdevice, such strapping consisting of; an elongated extruded plastic tapesubstantially longer than that portion thereof used for tying the bundleof conductors, the tape being of electrically insulating materialgenerally rectangular in section having a width about three times thethickness and with rounded corners, and a plurality of parallellongitudinally extending ribs on one surface of the width of the tapeand extending'throughout the entire length of the tape, the ribs havinga height small in relation to the thickness of the tape, a pointed edgeon each of the ribs defined by rib sides, the ribs positioned to lieparallel to one another and approximately equally spaced across thewidth of the tape.

2. Plastic strapping as in claim 1 wherein there at three identical ribslying parallel to one another at about one-fourth, one-half andthree-fourths the width of the tape.

3. Plastic strapping as in claim 2 wherein the height of the ribs isabout one-fifth to one-sixth the thickness of the tape and the pointededge is defined by the sides of the ribs merging at an included angle ofabout

1. Plastic strapping for passing around electrical conductors and the like and tying such conductors in a bundle using a separate locking device, such strapping consisting of; an elongated extruded plastic tape substantially longer than that portion thereof used for tying the bundle of conductors, the tape being of electrically insulating material generally rectangular in section having a width about three times the thickness and with rounded corners, and a plurality of parallel longitudinally extending ribs on one surface of the width of the tape and extending throughout the entire length of the tape, the ribs having a height small in relation to the thickness of the tape, a pointed edge on each of the ribs defined by rib sides, the ribs positioned to lie parallel to one another and approximately equally spaced across the width of the tape.
 2. Plastic strapping as in claim 1 wherein there are three identical ribs lying parallel to one another at about one-fourth, one-half and three-fourths the width of the tape.
 3. Plastic strapping as in claim 2 wherein the height of the ribs is about one-fifth to one-sixth the thickness of the tape and the pointed edge is defined by the sides of the ribs merging at an included angle of about 60*. 